Error:Execution failed for task ':app:mergeDebugAssets'

Question

I'm trying to make an app in Android Studio that opens a PDF file saved in the assets folder of the app when I tap a button. It opens the PDF through a 3rd-party app via intents.

I'm getting this error when I try to run it:

Error:Execution failed for task ':app:mergeDebugAssets'.

java.lang.NullPointerException (no error message)

My MainActivity.java code is:

public class MainActivity extends AppCompatActivity {

public void showPDF(View view) {
    Toast.makeText(MainActivity.this, "button pressed", Toast.LENGTH_LONG).show();
    //startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("pdfurl.pdf")));
    AssetManager assetManager = getAssets();
    File file = new File(getFilesDir(), "myfile.pdf");
    try {
        InputStream in = assetManager.open("myfile.pdf");
        OutputStream out = openFileOutput(file.getName(), 1);
        copyFile(in, out);
        in.close();
        out.flush();
        out.close();
    } catch (Exception e) {
    }
    Intent intent = new Intent("android.intent.action.VIEW");
    intent.setDataAndType(Uri.parse("file://" + getFilesDir() + "/myfile.pdf"), "application/pdf");
    startActivity(intent);
}

private void copyFile(InputStream in, OutputStream out) throws IOException {
    byte[] buffer = new byte[AccessibilityNodeInfoCompat.ACTION_NEXT_HTML_ELEMENT];
    while (true) {
        int read = in.read(buffer);
        if (read != -1) {
            out.write(buffer, 0, read);
        } else {
            return;
        }
    }
}




@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}
}

what do?

Answer 1

From the Stackoverflow question Read a pdf file from assets folder

p.s. try yo search around for your answer to keep from having duplicates. :)

public class SampleActivity extends Activity
{

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        CopyReadAssets();
    }

    private void CopyReadAssets(View v)
    {
        AssetManager assetManager = getAssets();

        InputStream in = null;
        OutputStream out = null;
        File file = new File(getFilesDir(), "abc.pdf");
        try
        {
            in = assetManager.open("abc.pdf");
            out = openFileOutput(file.getName(), Context.MODE_WORLD_READABLE);

            copyFile(in, out);
            in.close();
            in = null;
            out.flush();
            out.close();
            out = null;
        } catch (Exception e)
        {
            Log.e("tag", e.getMessage());
        }

        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(
                Uri.parse("file://" + getFilesDir() + "/abc.pdf"),
                "application/pdf");

        startActivity(intent);
    }

    private void copyFile(InputStream in, OutputStream out) throws IOException
    {
        byte[] buffer = new byte[1024];
        int read;
        while ((read = in.read(buffer)) != -1)
        {
            out.write(buffer, 0, read);
        }
    }
}

If this does not work! Let me know! But remember, look around a bit and maybe you'll find your question already answered.